You don't say what distro/version you're using, but I can offer the
following info about Red Hat RHL5's openldap offering: It's still not up
to scratch (to put it mildly), though better than that of RHAS4. A
couple of the reasons are, that it uses RH5's dbd 4.3.29, which is
deprecated for OL use and that it doesn't include all overlays.

I use RHL5/FC6/CentOS5 and rebuild Buchan Milnes' srpm(s) on all of
these: Buchan has done *all* the hard work for you, includes all the
overlays, includes a separate, self-contained patched db 4.2.52 - what's
more, it can coexist with RHL5's OL offering, if you don't want to go
the whole hog at once.

Red Hat/FC/CentOS people should *never* build from a virgin tarball
unless it's absolutely necessary, this statement after many years'
experience with both methods. In 99% of all cases, rpms or srpms are
available for all the above platforms.